Charging control for battery powered devices

Abstract

A method and apparatus for controlling the charge cycle of a rechargeable power source within portable electronic equipment is disclosed. When external power is applied to the portable electronic equipment, a determination is made of the present power capacity of the rechargeable power source for the equipment. If the present capacity is lower than a predetermined value, then a charge cycle is initiated. If the present capacity is not lower than the predetermined value, then a charge cycle is not initiated. Furthermore, the predetermined value may be fixed or adjustable by a user.

1 . An apparatus for controlling the charging of a rechargeable power source within an electronic device comprising: 
 a rechargeable power source;    a charge control circuit configured to charge said rechargeable power source;    logic to determine a present charge of said rechargeable power source; and    an auxiliary power source connectably attached to said charge control circuit;    wherein said charge control circuit is configured to initiate a charge cycle of said rechargeable power source after said auxiliary power source is connected to said charge control circuit and said present charge is below a predetermined value.    
   
   
       2 . The apparatus for controlling the charging of a rechargeable power source within an electronic device of  claim 1 , wherein said predetermined value is between approximately 25 percent and approximately 75 percent of a total capacity of said rechargeable power source.  
   
   
       3 . The apparatus for controlling the charging of a rechargeable power source within an electronic device of  claim 1 , wherein said predetermined value is threshold settable by a user.  
   
   
       4 . The apparatus for controlling the charging of a rechargeable power source within an electronic device of  claim 1 , wherein said rechargeable power source is a battery pack.  
   
   
       5 . The apparatus for controlling the charging of a rechargeable power source within an electronic device of  claim 4 , wherein said battery pack comprises battery cells selected from a group consisting of lithium ion cells, nickel metal hydride cells, nickel cadmium cells, lead-acid cells and lithium polymer cells.  
   
   
       6 . The apparatus for controlling the charging of a rechargeable power source within an electronic device of  claim 1 , further comprising: 
 a trickle charge circuit configured to provide a trickle charge to said rechargeable power source when said auxiliary power source is connected to said charge control circuit and said charge control circuit is not within said charge cycle.    
   
   
       7 . The apparatus for controlling the charging of a rechargeable power source within an electronic device of  claim 1 , wherein said charge control circuit also provides power to circuitry within said electronic device.  
   
   
       8 . The apparatus for controlling the charging of a rechargeable power source within an electronic device of  claim 7 , wherein said electronic device is a portable computer.  
   
   
       9 . A method for controlling the charging of a rechargeable power source within an electronic device comprising: 
 detecting connection to an alternate power source;    upon said detecting: 
 determining a present charge capacity of a rechargeable power source;  
 comparing said present charge capacity to a predetermined value; and  
 if said present charge capacity is less than said predetermined value, initiating a charge cycle.  
   
   
   
       10 . The method for controlling the charging of a rechargeable power source within an electronic device of  claim 9 , wherein said predetermined value is between approximately 25 percent and approximately 75 percent of a total capacity of said rechargeable power source.  
   
   
       11 . The method for controlling the charging of a rechargeable power source within an electronic device of  claim 9 , wherein said predetermined value is threshold settable by a user.  
   
   
       12 . The method for controlling the charging of a rechargeable power source within an electronic device of  claim 9 , wherein said rechargeable power source is a battery pack.  
   
   
       13 . The method for controlling the charging of a rechargeable power source within an electronic device of  claim 12 , wherein said battery pack comprises battery cells selected from a group consisting of lithium ion cells, nickel metal hydride cells, nickel cadmium cells, lead-acid cells and lithium polymer cells  
   
   
       14 . The method for controlling the charging of a rechargeable power source within an electronic device of  claim 9 , further comprising the step of: 
 providing a trickle charge to said rechargeable power source when said auxiliary power source is connected and when not in said charge cycle.    
   
   
       15 . The method for controlling the charging of a rechargeable power source within an electronic device of  claim 9 , wherein auxiliary power source is DC voltage provided from a power supply that in turn receives power from an AC line voltage.  
   
   
       16 . A notebook computer comprising: 
 a battery pack;    a charge control circuit configured to charge said battery pack;    logic to determine a present charge of said battery pack; and    an auxiliary power source connectably attached to said charge control circuit;    wherein said charge control circuit is configured to initiate a charge cycle of said battery pack after said auxiliary power source is connected to said charge control circuit and said present charge is below a predetermined value.    
   
   
       17 . The notebook computer of  claim 16 , wherein said predetermined value is between approximately 25 percent and approximately 75 percent of a total capacity of said rechargeable power source.  
   
   
       18 . The notebook computer of  claim 16 , wherein said predetermined value is threshold settable by a user.  
   
   
       19 . The notebook computer of  claim 16 , wherein said battery pack comprises battery cells selected from a group consisting of lithium ion cells, nickel metal hydride cells, nickel cadmium cells, lead-acid cells and lithium polymer cells.  
   
   
       20 . The notebook computer of  claim 16 , further comprising: 
 a trickle charge circuit configured to provide a trickle charge to said battery pack when said auxiliary power source is connected to said charge control circuit and said charge control circuit is not within said charge cycle.    
   
   
       21 . The notebook computer of  claim 16 , wherein said charge control circuit also provides power to circuitry within said notebook computer.